Biomedical research encompasses a wide range of fields. Today, one of the most important is the study of cellular and molecular biology and diseases that originate at the cellular and molecular level.
Experiments in cellular and molecular biology can often be characterized as a sequence of steps beginning with preparation of a culture of a specific cell type in a suitable growth medium. Portions of the cell culture and growth medium are then dispensed into experimental containers (e.g., flask, test tube, or well plate), allowed to grow for some period of time (perhaps in an incubator, bioreactor or fermentor), the condition of the cell culture is observed or measured (e.g., microphotograph or cell count) the cell culture is treated with a reagent (defined as any substance that is used in an experimental protocol) of interest, perhaps allowed to grow again, and then again observed or measured or subjected to further processing before being observed or measured. In some instances, an experiment may start from a cell extract such as proteins, nucleic acids, organelles or membranes, or from another substance which is then processed, observed and measured. Finally, the observations and measurements are compared and used to determine the effect of the protocol, treatment or reagent and to gather information on a biological, physical or chemical phenomenon.
The cells used for biomedical research are often cultured from established cell lines originating from deceased donors, but can also be cells taken from living humans or other species and cultured thereafter. The process of cell culture itself, i.e., how to ensure the survival, growth and proliferation of the cells follows principles well known to those skilled in the art.
Today, for the most part, such experiments are performed manually in academic, research, pharmaceutical, biotechnological and clinical facilities that vary widely in the available equipment, procedural conditions, and also in the experience and expertise of technicians and scientists conducting the experiments. Experiments performed in limited facilities may be performed with great care but vary in outcome because of variation in temperature, humidity, pH, sample volume, particle concentrations, gas concentrations, exposure to light, cross contamination from other experiments, viral and bacterial contamination from ambient air, and aerosol contamination from other experimental reagents and antimicrobials, and/or other factors.
Variations in procedural conditions thereby cause various biological effects. For example both temperature and pH change the activity of enzymes (normally consisting of proteins), which are at the core of almost every biological process. In addition, genes can be expressed more or less strongly depending on e.g., oxygen levels or temperature. And these changes in gene expression levels can then in turn cause widespread changes in cell behavior, metabolism etc. These changes in turn have a significant impact on general cellular processes, but also on the effect of drugs or other experimental treatments on a cell.